Frequently Asked Questions

Start by measuring your room's length, width and ceiling height. Then factor in variables such as the number of external walls, windows, insulation quality and floor type. These details feed into a BTU calculation that tells you exactly how much heat the room needs. We've built a heat calculator to make this straightforward: enter your room dimensions and it'll recommend the right radiator size for you. If you're unsure about any of the inputs, our team can walk you through it.

Cast iron heats up more slowly than steel, but it retains heat for far longer once it reaches temperature. That means your boiler cycles less frequently, because the radiator continues releasing warmth well after the system switches off. Over time, this thermal mass can reduce energy consumption, particularly in well-insulated homes. Steel radiators respond faster, which suits rooms you heat infrequently. For living spaces you want to keep consistently warm, cast iron is the more efficient choice. Read more in our guide to radiator efficiencies.

Our range covers a variety of heights to suit different room proportions and window sills. Compact two-column models sit lower beneath sash windows, and taller six-column radiators suit rooms where wall space is limited. Heights vary by model, so use our buying guide or speak to the team for specific dimensions on the model you're considering.

Yes. Heat pumps run at lower flow temperatures than traditional boilers, and cast iron's thermal mass works in your favour here: it absorbs and holds heat effectively even at those lower temperatures. You'll need to size your radiators carefully, because a lower Delta T means each section produces fewer BTUs. Our Delta T guide explains how to adjust your calculations. We'd always recommend discussing your specific heat pump setup with a qualified installer.

Cast iron radiators are substantially heavier than steel equivalents. Weight depends on the model, height and number of sections: a single section can weigh anywhere from around 8 kg for a smaller model up to 20 kg or more for larger ornate designs. A fully assembled radiator with 10 or more sections can be a significant load. This is worth considering for both delivery access and installation. Our guide to safely carrying and installing cast iron radiators covers this in detail.

In most properties built with standard timber joists or solid floors, reinforcement isn't necessary. The weight is distributed along the full length of the radiator and through the feet or wall stays, so the load per square metre is manageable. Where you might need to check is in older properties with weakened joists, or if you're placing a very large radiator on an upper floor. A structural survey is always sensible if you have concerns. Your heating engineer can advise during the installation survey.

You can use either manual or thermostatic radiator valves (TRVs). TRVs let you control the temperature room by room, which improves comfort and efficiency. We offer valves in a range of finishes including antique brass, brushed nickel, chrome and polished brass to complement your radiator's style. Take a look at our full valves and accessories range. If you're pairing cast iron with a smart heating system, TRVs are the better choice.

Copper and plastic pipework expand and contract as water temperature changes. With cast iron radiators, the key is to allow sufficient movement in the pipe runs. Use flexible connectors where pipework meets the radiator, and make sure pipe clips aren't fixed so tightly that they prevent natural movement. Your installer should leave a small gap where pipes pass through floors or walls. This prevents stress on joints and reduces the risk of leaks over time.

Cast iron radiators hold a large volume of water, so microbore pipework (8 mm or 10 mm) can restrict flow and slow heating performance. It's possible to use microbore with smaller radiators, but for most installations you'll get better results by upgrading to 15 mm pipework. If you're replacing existing radiators in a property with microbore throughout, discuss the options with your heating engineer before committing to a particular model and size.

Yes, wall stays are strongly recommended. Cast iron radiators are heavy, and wall stays prevent the radiator from tipping or shifting once installed. They also take some of the load off the floor, distributing weight between the feet and the wall. We offer wall stays in several finishes to match your valves, and they can be fitted at the front for a visible feature or concealed within the columns.

Absolutely. Cast iron and steel radiators work on the same wet central heating system without any compatibility issues. The main thing to be aware of is that cast iron takes longer to warm up, so rooms with steel radiators will reach temperature faster. You can balance your radiators to even things out, adjusting the lockshield valves so water flows to each radiator at the right rate.

Yes. A quality corrosion inhibitor is essential for any system containing cast iron. It protects the internal surfaces from rust and prevents sludge building up in the system. Your installer should add inhibitor when commissioning the system, and it should be topped up or refreshed whenever the system is drained. This is one of the simplest steps you can take to extend the life of your radiators and keep the system running efficiently. For more detail, read our maintenance guide.

Yes. Cast iron radiators work well on sealed, pressurised systems, which are the standard in most modern UK homes. Just make sure the system pressure is set correctly and that your expansion vessel is sized to handle the additional water volume that cast iron radiators hold. Your installer can check this during commissioning. There's no need for any special fittings or adaptors beyond the standard valves and connections.

Bleeding a cast iron radiator is the same process as any other radiator. Turn off the heating, let the system cool slightly, then use a bleed key or the keyless air vent to open the bleed valve at the top of the radiator. You'll hear air escaping: once water starts to trickle out, close the valve. All our radiators come fitted with a brass air vent as standard, with the option to upgrade to our luxury knurled keyless air vents. Read our full guide to bleeding radiators for a step-by-step walkthrough.

Every Paladin radiator is finished to your specification before it leaves our Lincolnshire workshop. You can choose from our standard colour range, select a shade from Farrow & Ball or Little Greene, or send us a colour to match through our bespoke colour matching service. We also offer specialised paint effects and hand polishing for a true one-off finish. Your radiator arrives ready to install: no priming or painting needed on site.

You can, but we'd recommend having them factory-finished instead. Factory application in controlled conditions gives a more durable, even coat than painting on site. If you do need to touch up or repaint, use a high-quality radiator paint designed for high temperatures, and make sure the surface is clean and lightly keyed. Our guide to painting cast iron radiators covers preparation, application and the best paints to use.

Cast iron radiators are built from individual sections that are joined together with threaded nipples and sealed with gaskets. This sectional construction means your radiator can be made to the exact width you need: just add or remove sections. It also makes servicing easier, because a damaged section can be replaced without scrapping the whole radiator. Our guide to joining a split cast iron radiator explains how this works in practice.

Yes, and the range is broader than most people expect. We make everything from heavily ornate models like the Kensington and Oxford with intricate period detailing, through to cleaner traditional column designs like the Neo Georgian that suit both period and contemporary interiors. Our guide to understanding styles helps you narrow down the right look for your project.

We deliver nationwide from our Lincolnshire workshop. Radiators are securely wrapped and palletised to protect the finish during transit. For larger orders or multi-room projects, we can schedule delivery to coordinate with your build programme. Specific delivery details, including lead times and access requirements, are covered on our delivery options page. If site access is restricted, let us know in advance and we'll work out the best approach.

A leak between sections usually means a nipple joint has loosened or a gasket has failed. Drain the radiator, separate the leaking sections using a radiator spanner, replace the gasket and re-tighten. It's a straightforward job for an experienced installer. Our guide to joining a split cast iron radiator walks through the process step by step. If you're not confident tackling it yourself, contact a heating engineer familiar with cast iron systems.

Not if they're properly protected. Externally, a good-quality paint finish seals the iron from moisture: all Paladin radiators leave our workshop fully finished and ready for installation. Internally, a corrosion inhibitor added to the central heating system prevents rust from forming. Problems tend to occur when inhibitor levels drop or when radiators are left drained and exposed to air for extended periods. Regular system maintenance keeps rust at bay. Our guide to why radiators rust explains what to watch for.

Yes. Cast iron radiators work well in bathrooms, and their heat retention is a real advantage in a room you want to keep warm between uses. Make sure your bathroom has adequate ventilation to manage moisture, as persistent dampness around any radiator can affect the finish over time. Browse our bathroom radiator ideas for inspiration.

Paladin cast iron radiators come with a 10-year guarantee. This reflects the durability of cast iron as a material and our confidence in the quality of our manufacturing. Every radiator is hand-assembled, pressure-tested and finished at our Lincolnshire factory before it reaches you. For full warranty details and terms, visit our terms and conditions page or speak to our team directly.

Yes. Cast iron radiators cost more upfront than pressed steel alternatives, but they're built to last generations rather than decades. The material itself is exceptionally durable, resists corrosion when properly maintained, and retains heat long after your boiler switches off: that thermal efficiency can lower your energy bills over time. Beyond performance, they add genuine character and value to a property in a way that standard convector radiators simply don't. Every Paladin radiator is hand-assembled at our Lincolnshire factory and comes with a 10-year guarantee, so you're investing in something that'll outlast most other fixtures in your home.

They are, though they work differently to steel. Cast iron takes longer to reach full temperature, but once warm it holds and radiates heat steadily for an extended period. This means your boiler doesn't have to fire as often to maintain a comfortable room temperature. In well-insulated homes, that slower heat release is a real advantage. Cast iron also produces a higher proportion of radiant heat compared to convected heat, which many people find more comfortable: it warms objects and surfaces in the room rather than just the air. Our radiator efficiency page explains this in more detail.

It depends on what you mean by "best." If you want fast response and quick warm-up, steel panel radiators with convector fins heat the air rapidly. If you want deep, lasting warmth that feels more natural and stays in the room longer, cast iron is the stronger choice. Cast iron produces a blend of radiant and convected heat, which creates a more even temperature throughout the room without the hot-and-cold cycles you sometimes get with lightweight radiators. For rooms you spend the most time in, that consistent warmth makes a noticeable difference. Browse our full range of cast iron radiators to find the right model for your space.

If your existing cast iron radiators are still structurally sound, consider refurbishing rather than replacing them. Cast iron lasts well over a century with proper care, so age alone isn't a reason to remove them. If sections are cracked or the system is beyond repair, the best replacement for cast iron is new cast iron: you'll keep the same heat characteristics, aesthetic appeal and longevity. Modern cast iron radiators from Paladin are compatible with contemporary boiler and heat pump systems, so you get period style with up-to-date performance. Our guide to choosing a radiator can help you find the right fit.

Not necessarily. Twenty years is well within the lifespan of a quality cast iron radiator: many last 50 years or more without issue. If your radiators are heating evenly, holding pressure and showing no signs of corrosion or leaks, there's no technical reason to replace them. What you might consider is upgrading your valves to thermostatic radiator valves for better room-by-room control, or having the system power-flushed to clear any sludge build-up. Our guide on when to replace your radiator covers the signs that genuinely warrant a swap.

The main trade-offs are weight and warm-up time. Cast iron radiators are substantially heavier than steel, which means installation takes more effort and you'll need wall stays to secure them properly. They also take longer to reach full temperature, so they're not ideal if you only heat a room for short bursts. Cost is another consideration: cast iron typically costs more than steel, both for the radiator itself and for installation. That said, the longer lifespan, superior heat retention and the character they bring to a room more than offset those drawbacks for most homeowners. Our buying guide helps you weigh up the decision.

Regular cleaning keeps your radiators looking and performing their best. Dust between the columns with a long, narrow brush or a vacuum cleaner nozzle. For the painted surface, a soft damp cloth is all you need: avoid abrasive cleaners that could damage the finish. On the system side, make sure your inhibitor levels are checked annually and bleed any trapped air at the start of the heating season. Our complete maintenance guide covers everything from seasonal upkeep to long-term care.